1. Field of the Invention
The invention relates generally to the fields of autoimmunity and inflammatory bowel disease and more specifically to serological and genetic methods for diagnosing a clinical subtype of Crohn's disease.
2. Background Information
Inflammatory bowel disease (IBD) is the collective term used to describe two gastrointestinal disorders of unknown etiology: Crohn's disease (CD) and ulcerative colitis (UC). The course and prognosis of IBD, which occurs world-wide and is reported to afflict as many as two million people, varies widely. Onset of IBD is predominantly in young adulthood with diarrhea, abdominal pain, and fever the three most common presenting symptoms. The diarrhea may range from mild to severe and in ulcerative colitis often is accompanied by bleeding. Anemia and weight loss are additional common signs of IBD. Ten percent to fifteen percent of all patients with IBD will require surgery over a ten year period. In addition, patients with IBD are at increased risk for the development of intestinal cancer. Reports of an increasing occurrence of psychological problems, including anxiety and depression, are perhaps not surprising symptoms of what is often a debilitating disease that strikes people in the prime of life.
Progress has been made in diagnosing IBD and in distinguishing, in many cases, Crohn's disease from ulcerative colitis. However, CD and UC each can represent a number of distinct disease subtypes that affect the gastrointestinal tract and produce similar symptoms. The heterogeneity underlying CD, for example, can be reflected in the variable responses of CD patients to a particular treatment strategy. The availability of methods for diagnosing clinical subtypes of CD would represent a major clinical advance that would aid in the therapeutic management of CD and would provide a basis for the design of treatment modalities that are specific to a particular disease subtype. Unfortunately, a method of stratifying CD into clinical subtypes to allow the design of more precise treatment strategies is currently not available. Thus, there is a need for a method of diagnosing clinical subtypes of CD. The present invention satisfies this need and provides related advantages as well.